Transcription
Hey, welcome back. It's Medicosis Perfectio Alice. We have been talking about poikilocytosis for a while—poikilocytes, or abnormally shaped red blood cells. They include stuff like dacrocytes, schistocytes, spherocytes, acanthocytes, echinocytes, stomatocytes, elliptocytes, and target cells.
We have shifted our attention to intracellular inclusions, which is stuff included in the red blood cells, such as Howell-Jolly bodies, parasites in the red blood cells, also polychromasia. Last, we have nucleated red blood cells. Is the nucleus considered an inclusion? The answer is yes, because normal red blood cells do not have a nucleus. Our RBCs are circular, biconcave, non-nucleated. So, a nucleus inside of your red blood cell, unless you are a neonate, is always abnormal.
Here is our nice slide of hematopoiesis. Here we have the multipotent stem cells in your bone marrow. We have myeloid and lymphoid stem cells. The myeloid stem cells will give rise to a lot of stuff, including the red blood cells. In order for us to get from here to mature red blood cells, the cells start to be bigger and end up being small. They start with a nucleus; they end up non-nucleated. Okay, the first non-nucleated cell to appear is your glorious reticulocyte. For the reticulocyte to mature to be an erythrocyte, it takes three days. The reticulocytes, although non-nucleated, it still has some ribosomal material remnants, which gives it its blue color, called polychromasia. So the moral of the story is: immature cells are large and nucleated; mature cells are small and non-nucleated.
So, nucleated red blood cells or normoblasts are normal in neonates. After the neonatal period, abnormal causes include, but are not limited to: bone marrow damage—could be myelofibrosis or myelo-dysplastic syndrome, which is bone marrow infiltration; severe hemolysis—why? Because in hemolysis, your red blood cells are being destroyed; the bone marrow is working like crazy to produce more red blood cells, and it doesn't care if this cell is immature; just go, hustle, hustle. Also, bring more, more, more. But its motto is: "go, please go, bring these cells out so we can survive. I don't care if they are slightly immature or immature, period; just bring them out." That's the crazy bone marrow during severe hemolysis. Acute hemorrhage—same stuff; we are losing blood; we need more blood, and I don't care if it's immature. Leukemia—if your bone marrow is sick and has cancer cells in it, of course your red blood cells are not going to be happy and mature, and well, you'll end up with ugly red blood cells.
Leukoerythroblastic picture. This is a crazy condition where you have immature bone marrow white blood cells and immature nucleated red blood cells. So you end up with immature white blood cells and immature red blood cells, which is like being crazy and stupid.
Now pay close attention here: the presence of a large amount of nucleated red blood cells, which are these immature losers, will artificially raise your white blood cell count, because the analyzer, the machine that measures the blood and gives you the complete blood count, cannot differentiate between white blood cells and immature red blood cells. The machine cannot tell the difference. So if these cells are increased, the white blood cell count will be increased. What's the solution? The lab technician or pathologist has to look at them individually, manually, okay, to make sure that these cells—no, they are not white blood cells; these are immature red blood cells—and he will write down in the report: "I found some normoblasts," or the pathologist can write: "I have here unexplained normoblasts," or "I see many normoblasts in the blood." And, of course, normoblasts are the immature red blood cells.
So here is an illustration to help you understand the whole thing. If you have hemolysis or acute blood loss, now your bone marrow is working like crazy—increased hematopoiesis. This will lead to increased reticulocytes in the blood, which is called reticulocytosis, as well as the presence of nucleated red blood cells in the blood, known as normoblastemia. On the other hand, if you have myelofibrosis or myelodysplasia, which is infiltration of the bone marrow via stuff such as tumor, you will end up with low reticulocytosis, because basically your bone marrow is now useless, and also nucleated red blood cells, because your bone marrow is such a loser; it cannot produce normal red blood cells.
So the moral of the story: nucleated red blood cells can be present in any of these cases. The reticulocyte count will help you determine which is which. And that's it for today. I'll see you in the next video. Please don't forget to subscribe. Thank you.